The problems associated with statically charged air particles in the vicinity of sensitive manufacturing processes and sensitive work pieces are well known. The buildup of static charges on sensitive electronic components may lead to severe damage of those components. Defective electronic components may not be discovered until later part of a larger assembly that fails in the field, in which case often a much higher-dollar assembly must be repaired or returned.
Air ionizing apparatus are also not new. Partridge U.S. Pat. No. 5,055,963 (issued Oct. 8, 1991) describes air ionizing apparatus that produces a balanced number of positive and negative ions. It is important that the numbers of positive and negative ions produced are approximately equal, so as not to actually contribute to the problem of static discharge in the vicinity of the work piece. In Partridge, dispersal of the ions is accomplished by a fan that is housed in the device. The fan directs an airflow through the electrode region into the workstation.
Le Vantine U.S. Pat. No. 4,635,161 (issued Jan. 6, 1987) also describes an air ionizing device. Separate helical streams of positive and negative ions are mixed in a vortex chamber, and exit through small airjets. This device requires separate air supplies for the positive and negative electrodes, and a carefully designed chamber and nozzle to properly mix and disperse the ions.
The prior art further includes air ionizing rings fabricated of metal, that provide high pressure gas flowing through a small gap in the ring and then through the opening past the electrodes. These devices are expensive to manufacture, however, because they are comprised of precision machine parts to meet the tolerances of providing the small gap through which the gas flows. Some devices use shims to provide the small gap, but this adds extra parts and costs. Whether the small gap is machined in or built up with shims, the inner curved surfaces of the ring must be carefully machined to provide for a smooth flow of air through the ring.
Although such devices as described above have proven generally suitable for their intended purposes, they possess inherent deficiencies which detract from their overall effectiveness in the marketplace. Requiring a fan to be housed in an air ionizer leads to cost and complexity. Requiring two air supplies and a chamber and nozzle to mix and disperse ions is also needlessly complex. Requiring complex machined parts to make up an air ionizer is expensive.